It could be a matter of taste, and a matter of a different perspective because I confess that I could give writer Greg Pak a pass with this line-up but still be more critical with his other run, Action Comics which stars Superman since my expectations has more weight with the latter. I think that my state of mind going into this collected volume affected my overall judgment which also helped my enjoyment of the story and characterization. I would also want to disclose that I'm a Bats-Sups shipper (I adore their relationship, platonic or OTHERWISE) so that bias is my rose-colored lenses while reading this.
Nevertheless, I would still remain objective in this review because I don't want to give misinformation to anyone who is interested in perhaps giving this a try; as you well should. It's not everyone's cup of tea but it might just be yours so don't dismiss it based on the very negative reviews you may have encountered.
The direction of Pak's writing is something that doesn't fit from what you might expect in a tights and cape comic book. This for me is actually okay but I do acknowledge that the delivery of the plot and characters as a whole can be the most jarring and nonsensical thing ever produced on a superhero story yet. The first four issues deal with more character exposition which for someone who likes that sort of thing would easily get into it, but might be detested by readers who expect more from the plot development. However, I can't even say Batman-Superman is a character-driven story because I don't think the approach has been done well in the four issues I've read. There are paper-thin moments among chief characters and some interactions do feel quite stiff. As for the plot in general, this is the most aspect of this volume that has been criticized and rightly so. Truly nothing remarkable happens in the storyline for the the four issues (and arguably nothing at all). The action sequences can feel diluted too when you don't know what the hell is supposed to be happening at the moment.
In addition to this, the Batmen and Supermen of two worlds don't really have much impact to the storyline. They serve more as chess pieces to a bigger game that they're not actually going to be players of; at least that's how I viewed it. This is easily frustrating then, because this is the World's Finest we are talking about; a pairing of overwhelming strength and legacy most especially when you have them together, fighting for the same things. I never get a sense of that urgency and awesomeness for the four issues and it therefore made the plot even more underwhelming when it reaches its conclusion. My review for issue #4 was particularly lukewarm. I was unhappy with how it wrapped up. It was already in a shaky ground to begin with and then we get that kind of pay-off which isn't satisfying at all. Sure, I could give a pass because history dictates that most World's Finest stories haven't been in any kind of superior standard in comparison to other DC titles (Green Arrow-Green Lantern issues are more exciting and the more commendable superhero pairing, truth be told). But with the New 52 launch, I've always maintained a gravity of expectations that have been fulfilled by other titles (Bat-family mostly) so I wanted Batman-Superman to be one of those. In some aspects, it was.
A great number of comic book readers will agree unanimously that Jae Lee's artwork is the most amazing thing about this volume (even those who don't consider Lee to be one of their favorite artists in comics right now have some good things to say about his style and layout). I admit that this is the second draw for me when I bought the volume. The majestic cover depicting Superman and Batman together that resemble a huge statue of some kind in real life is just so damn visually pleasing to look at. Lee's uniquely styled illustrations and quaint structural panels got me through reading the issues, and even increased my enjoyment some more because his drawings are just an adventure to peruse through by themselves.
As I've said before, being a Bats-Sups shipper makes me giddy over anything that includes them both in the pages (I'm prepared to enjoy the Dawn of Justice film coming out in 2016 only because I'll finally get to see live-action Bats-Sups together on screen). It's an added bonus that other JLA members are not in focus (sure, Wonder Woman makes an appearance but she hardly does anything substantial except fight pretty which is saying something horrible about the writing as well). My favorite moments will always be the character monologues between New 52 Batman and Superman that highlight how much they don't like each other and cannot work together, and that flashback sequence where we find out how Earth-2 Bats and Sups became besties in childhood. This is why the third issue is my most favorite of all because it made my shipper heart skip several beats while reading. But again, this is a very subjective way of reading Batman-Superman that you will not share unless you consider World's Finest as a great pairing in general (which I do and you don't need to agree with me because I frankly won't give a damn if you don't).
Finally, I think it's worth mentioning that this volume has got to have the best bonus material in the last pages. New 52 DC titles lately when they go deluxe or hardcover editions would only feature variant covers (maybe a copy of a manuscript for a select issue) and that's it. But with Batman-Superman, we get pages of the writer and artist talking about the process of writing and illustrating their issues. It's a great read because you get an insider's look on how a comic book is made. It features the pencils stage for Lee's artwork all throughout while we get interviews from the people who worked for this title discussing the decisions they've made and why they chose that layout or panel sequencing, etc. For this alone, I'm glad I bought the volume.
However, don't buy the volume if you're not completely a DC fan, particularly of Batman and Superman together in one book. I still recommend you give this a chance and read it but not own a hard copy yourself because I don't think you will get your money's worth if it turns out this is not your cup of tea. Even though I'm giving this a better rating than most, I still have several things I dislike about this volume but they are ones I could overlook. But you might not, so that's an important difference between you and I.